A seat reclining apparatus for a vehicle configured to retain a seatback in an unlock state where the seat back is released from being locked by a recliner at a predetermined inclination angle range is known. By a provision of a retention mechanism, an inclination angle of the seatback may be largely changed without maintaining an unlock operation input. In addition, the seat reclining device includes an operation input portion, for switching the recliner to the unlock state, disposed at an operable position from a backward of the seatback.
For example, a seat reclining device disclosed in Patent document 1 includes a forward inclination operation lever provided at an upper end of a seatback, and a link lever rotating on a basis of an operation input of the forward inclination operation lever. A recliner is shifted to an unlock state by rotating the link lever. In addition, the seat reclining device includes a cam plate that may restrict the link lever from rotating. The cam plate restricts the link lever from rotating by engaging with the link lever that rotates in conjunction with the forward inclination operation lever. The cam plate is retained in an engaged state with respect to the link lever at a predetermined inclination angle range that is set forward of a neutral position corresponding to a basic position of the seatback.
The seatback reclining apparatus of the known example may largely incline the seatback forward without maintaining the operation input relative to the forward inclination operation lever based on the engagement relationship between the link lever and the cam plate. The seat reclining device may return the seatback to a fixed point that corresponds to the basic position of the seatback irrespective of an inclination angle before the forward inclination operation by pulling up the seatback.
The seat reclining apparatus of the known example includes a reclining operation lever that is separately provided from the link lever and the cam plate with which a retention mechanism is configured. The reclining operation lever is provided at a side of the seat cushion. The reclining operation lever may adjust the inclination angle of the seatback at the forward of the basic position of the seatback by unlocking the recliner based on the operation input relative to the reclining operation lever.
However, there is a case where only one operation system of the seatback is set in a seat for a vehicle, for example, a rear seat. In this case, according to the aforementioned known technology, the return position by the pulling up operation may accord with a first stage position of an adjustable range of the inclination angle of the seatback.